1. Field
The present disclosure relates generally to inspection and in particular to nondestructive inspection. Still more particularly, the present disclosure relates to a method and apparatus utilizing a plurality of mono-energetic, directional x-rays and the x-ray images of an object generated at multiple discrete x-ray energies to increase the sensitivity of nondestructive inspection of an object.
2. Background
A manufactured object may have sub-surface inclusions, fine porosity, or other anomalies that may make the structure unsuitable for its intended use. Therefore, nondestructive inspection of the object may be needed. Current nondestructive inspection techniques may include conventional polychromatic x-ray radiography, neutron radiography, and ultrasonic techniques. However, the current x-ray radiographic sensitivity in inspection is limited by the combination of the penetrating power of the x-ray, the polychromatic nature of the x-rays, and the scatter field intensity of the scattered radiation.
In addition, the detection of fine detail in material samples using conventional x-rays is often limited by the contrast available at the energy of the x-ray beam. This problem exists for inspection of large items, such as, without limitation, container inspection at ports, as well as inspection of small objects, such as castings for aerospace. Thus, it would be advantageous to have a method and apparatus that overcomes the problems of the limited sensitivity of non-destructive inspection.